Abstract:
Embodiments of thermal-acoustic sections for an aircraft for reducing noise along an acoustic path produced from an acoustic source are provided herein. The thermal-acoustic section comprises a first porous layer having a first characteristic acoustic impedance. A second porous layer is disposed adjacent to the first porous layer and has a second characteristic acoustic impedance that is greater than the first characteristic acoustic impedance. The thermal-acoustic section is configured to be positioned along the acoustic path such that at least a portion of the noise from the acoustic source is directed through the first porous layer to the second porous layer to promote absorption of the noise.
Abstract:
Die Erfindung betrifft ein Verfahren zur Herstellung eines Bauteilverbundes (70, 140) umfassend eine Befestigungsstruktur (60, 160) umfassend wenigstens eine Bauteillage (60A, 60a;160a, 160b) und ein thermoplastisches Verbindungselement (10, 110) aufweisend einen Kopf (12, 112) und einen Schaft (14, 114), wobei das Verbindungselement (10, 110) unter Rotation und Druck in die Befestigungsstruktur (60, 160) eingetrieben wird, so dass der Schaft (14, 114) die Befestigungsstruktur (60, 160) durchdringt, wobei das Verbindungselement (10, 110) nach Durchdringen der Befestigungsstruktur (60, 160) an einer Matrize (44, 144) unter Reibung in einen erweichten, fließfähigen Zustand gebrachtwird, die entgegen der Eintreibrichtung an der Befestigungsstruktur (60, 160) angelegt wird, so dass sich eine über die bereichsweise radiale Ausdehnung des Schafts (14, 114) hinaus erstreckende Verdickung (22, 22) ergibt, wobei die Befestigungsstruktur (60, 160) zwischen Kopf (12, 112) und Verdickung (22, 122) formschlüssig gehalten wird.
Abstract:
A composite sandwich structure comprises a core sandwiched between composite laminate facesheets. The core includes a plurality of core sections spliced together at joints that incorporate integral features for arresting the propagation of irregularities in the facesheets.
Abstract:
A method of manufacturing an elbow channel (1) with an elbow angle (a). The method comprises manufacturing an elongated filament-reinforced plastic composite hollow body (2) by a filament winding technology; miter-cutting the elongated hollow body (2) at a cut angle (a/2), which is half of the desired elbow angle (a), to form a first body piece (3) having an oblique first end (4), and a second body piece (5) having an oblique second end (6); placing the first body piece (3) and the second body piece (5) in relation to each other to abut the first end (4) and the second end (6) against each other, so that the longitudinal symmetry axes (x) of the first and second body pieces are at said elbow angle (a) to each other; and attaching the first end (4) and the second end (6) to each other to form said elbow channel. The elbow channel (1) is formed from first and second hollow body pieces (3, 5) which are miter cut at a cut angle (a/2) from an elongated filament-wound filament-reinforced plastic composite hollow body (2), the hollow body pieces (3, 5) being connected to each other at their miter cut first and second oblique ends (4, 6) to form the elbow channel.